Present pointer touchpad devices, which are basically stationary pointing devices, allow for the manipulation of a cursor icon or pointer on a graphic display (i.e., monitor) of a computer by a user. Current pointer touchpad devices operate in accordance with a coupling capacitance principle, wherein a conductive pointer, such as a finger, is used in conjunction with a two-layer grid of electrodes to provide for the movement of a cursor icon on the graphic display of a computer. The top layer of the two-layer grid contains a vertical series of electrode strips, while the bottom layer contains a series of horizontal electrode strips, the respective electrode strips are connected to an integrated circuit which measures the capacitance associated with each of the electrode strips.
The conductive pointer (i.e., finger), when applied to the pointer touchpad device, alters the capacitance between the respective strips, as the conductive pointer (i.e., finger) possesses very different properties than air. Accordingly, the position of the conductive pointer (i.e., finger) is determined based upon the difference in the capacitance between the respective electrode strips. The capacitance difference is translated from the two-layer grid of electrodes to a corresponding cursor icon contained on a graphic display of a computer which corresponds to or tracks the movement of the conductive pointer on the two-layer grid of electrodes.
Accordingly, the standard pointer touchpad device allows for the manipulation of a cursor icon or pointer on a graphic display, but does not typically provide any ancillary use or function besides cursor control. Presently, however, there is an effort to consolidate system periphery components into single multi-functional device in order to reduce the number of peripheral components and simplify the overall complexity of computer systems. Fingerprint recognition devices, however, have remained a separate and distinct component in most secure computer systems due in part to the fact that they are not easily consolidated or merged into existing system peripheral components.
Correspondingly, as more and more computer systems are incorporating the use of separate fingerprint recognition devices, in order to provide for system security, the need to consolidate the fingerprint recognition devices into existing peripheral components grows as the demand for simplified single multi-functional devices increases.
Fingerprint recognition devices provide for computer system security by verifying the identity of a user, via fingerprint authentication, before allowing the user access to the system or a secure application. Current fingerprint recognition devices are typically external to the to the computer system and are usually coupled to the computer system through a cable or other input device. The typical external fingerprint recognition device typically comprises an illumination source, a prism which contains a sensing surface for fingerprint placement, and a detection array. Accordingly, a fingerprint image is authenticated by the fingerprint recognition device by obtaining a reflected fingerprint image and comparing the reflected image to a database containing fingerprint images or data associated with authorized users.
Fingerprint authentication is typically used to selectively restrict access or entry to secure applications or to a secure computer system by restricting access only to authorized personnel. For instance, if a user attempts to gain access to a secure computer application, the computer system would prompt the user to place a select finger onto the external fingerprint recognition device for fingerprint authentication. Next, a fingerprint authentication takes place verifying whether or not the user is authorized to access the selected secure computer application. Accordingly, the fingerprint authentication process grants access or entry only to authorized users, while denying unauthorized access to other users who are not authorized for entry or use of the secure system.
Currently, secure computer systems, which require fingerprint authentication, utilize a separate pointer touchpad device for cursor control and a separate fingerprint recognition device for fingerprint authentication. Correspondingly, the use of two separate peripheral devices for two different functions (i.e., cursor control and fingerprint authentication) results in increased cost and complexity of operating a secure computer system. The cost is mainly attributed to the required support structure and circuitry necessary for operating two separate devices (pointer touchpad device and fingerprint recognition device) in a secure computer system. For instance, the pointer touchpad device requires a two-layer grid of electrodes, cursor control interface, and supporting circuitry in order to provide for the movement of a cursor icon on a graphic display of a computer. Likewise, the fingerprint recognition requires an illumination source, a prism, and a detection array, comparison database, and supporting circuitry in order to provide for fingerprint authentication.
With the ever increasing goal of reducing the size, number, and complexity of existing and peripheral components into a single multi-functional low cost component, the use of two separate components (pointer touchpad device and fingerprint recognition device) is counterproductive, as the use of two separate components translates to an increase in cost and complexity of secure computer systems which require the use fingerprint authentication.
It is therefore desirable to provide a multi-functional touchpad device which is capable of performing the individual tasks of manipulating a cursor icon on a graphic display of a computer and performing fingerprint authentication, within a singular multi-functional device.